At present, 4G radio communication systems have been standardized by the Third Generation Partnership Project (3GPP). In 4G, technologies such as carrier aggregation, relay, and Multi-User Multiple-Input Multiple-Output (MU-MIMO) have been noticed.
In particular, carrier aggregation is a technology capable of collectively handling, for example, five frequency bands with a bandwidth of 20 MHz to handle a bandwidth of 20 MHz×5=100 MHz. According to carrier aggregation, an advance in the maximum throughput is expected. Various technologies related to such carrier aggregation have been investigated.
For example, Patent Literature 1 discloses a technology for suppressing deterioration in throughput by controlling assignment of a measurement gap for each component carrier (CC) based on a determination result of urgency of handover.